ri702bill 9,258 #1 Posted June 16 (edited) While mowing last week with my 854, it lost power & died. No spark. No arcing at points.... NO continuity on the primary winding of the coil (I figure the internal resistor went on permanent vacation.) The "Parts Department" coughed up three possible replacements - two with the standard internal resistor from engines I have heard run before and one oddball. Looks to be a Standard Motor Products 1303 that states that an external resistor is required. That was on a C81 parts tractor with the connecting rod thru the block - never heard that one run, never will. Has anyone used this style, wired like an old Slant 6 or 1960's Chevy with two positive wires - a "start" wire from the solenoid to deliver full 12 volts and a second "run" wire with a ballast resistor that would be the same as the original internal resistor type??? It is supposed to make the coil output a hotter spark while starting. I do have a solenoid on this one too. Any thoughts?? Edited June 16 by ri702bill 1 Share this post Link to post Share on other sites
ebinmaine 72,080 #2 Posted June 16 We've had a "parts" tractor in the past that had that here. Like you, I never heard it run. That particular coil was badly dented so I heaved it. Interesting idea.... Share this post Link to post Share on other sites
953 nut 59,459 #3 Posted June 16 There is no reason you couldn't run an external resistor like the ones used on Chrysler products if that is what you want to do. 2 Share this post Link to post Share on other sites
squonk 43,537 #4 Posted June 16 16 minutes ago, 953 nut said: There is no reason you couldn't run an external resistor like the ones used on Chrysler products if that is what you want to do. Keep one in your glove box just like the old days! 1 2 2 Share this post Link to post Share on other sites
pfrederi 18,586 #5 Posted June 16 I would not use the external resister.. They get very hot. If you were out plowing snow /snow blowing and it hits the resister you are dead in the snow... 2 Share this post Link to post Share on other sites
ri702bill 9,258 #6 Posted June 16 2 hours ago, squonk said: Keep one in your glove box just like the old days! Had to do just that on my wife's '73 Coronet ( and a spare module on any 1970's GM I owned...) Share this post Link to post Share on other sites
ri702bill 9,258 #7 Posted June 16 13 hours ago, ri702bill said: Looks to be a Standard Motor Products 1303 that states that an external resistor is required I played "Musical Coils" this morning - swapped out all three, one at a time. All three work. Ballast location - maybe that was why Chrysler mounted them up high on the firewall?? How about locating it inside the steering tower - would double as a hand warmer! Share this post Link to post Share on other sites
squonk 43,537 #8 Posted June 16 29 minutes ago, ri702bill said: Had to do just that on my wife's '73 Coronet ( and a spare module on any 1970's GM I owned...) My Mom's 76 Dart ! and a spare pick up coil in my 84 dodge Rampage! Share this post Link to post Share on other sites
WHX?? 51,555 #9 Posted June 16 I have no problem with the resistor required type on the flame. Hard to find a chromie that doesn't need it. 1 Share this post Link to post Share on other sites
squonk 43,537 #10 Posted June 16 1 hour ago, WHX?? said: I have no problem with the resistor required type on the flame. Hard to find a chromie that doesn't need it. Accel 8140C internally resisted. 2 Share this post Link to post Share on other sites
Stepney 2,353 #11 Posted June 17 Far as I know the externally resisted coils really only exist because it was cheaper to replace just a ballast in any of the millions of cars on the road back in the day, opposed to swapping an otherwise perfectly fine coil just because the resistance winding failed. For the few bucks difference anything 12v I own just gets a internally resisted coil, do away with the ballast and clean things up a bit. Funny .. My '55 Ford is a 6v car and even that has a resistor in series with the distributor. Never could explain that.. Don't think any of these tractors ever came through with a ballast though. Just one more thing in the way, subject to vibration, and they're fragile. ..Just don't go running a external resistor coil without a resistor .. It may be fine for decades .. or it may explode and shoot scalding oil everywhere like my old Case did.. Share this post Link to post Share on other sites
kpinnc 14,381 #12 Posted June 17 On 6/15/2025 at 8:41 PM, ri702bill said: Has anyone used this style, I used an external resistor type several years back on a K241. It worked just like the internal resistor type. The large resistors are available at most parts stores. Share this post Link to post Share on other sites
ri702bill 9,258 #13 Posted June 17 That is the exact one that went "Paws UP" on me, hence this discussion. I did find a location I like for mounting the ballast should I choose to go that route. Horizontal mounted to the battery box between the battery & engine. Makes for short runs of wire..... Hidden out of sight. Share this post Link to post Share on other sites
ri702bill 9,258 #14 Posted June 17 7 hours ago, Stepney said: subject to vibration, and they're fragile. Yup, vibration (and sudden thermal changes) are not electrical components friends. Running the external resistor style without the resistor sends a full 12 volts, or upwards to 13.8 while running, to the points. That causes arcing, burning & pitting of the contacts at a rapid rate. If I go the external route, maybe I'll get two and install the firsy with a wingnut... Share this post Link to post Share on other sites
